1. Field of the Invention
The present application relates to an aspiration tube for a medical aspiration system.
2. Prior Art
The lens of a human eye may develop a cataracteous condition which affects a patients vision. Cataracteous lenses are sometimes removed and replaced in a procedure commonly referred to as phacoemulsification. Phaco procedures are typically performed with an ultrasonically driven handpiece which is used to break the lens. The broken lens is removed through an aspiration line that is coupled to the handpiece.
The handpiece has a tip which is inserted through an incision in the cornea. The handpiece typically contains a number of ultrasonic transducers that convert electrical power into a mechanical oscillating movement of the tip. The distal end of the tip has an opening that is in fluid communication with the aspiration line. The distal end of the tip also has a sleeve which has an opening in fluid communication with an irrigation line. The irrigation line is typically connected to a bottle that can provide irrigation fluid to the surgical site.
The oscillating movement of the tip will break the lens into small pieces. The lens pieces and irrigation fluid are drawn into the aspiration line through the opening of the tip. When performing a phaco procedure it is essential to maintain a positive pressure within the anterior chamber of the eye. A negative pressure may cause the cornea to collapse. To maintain a positive chamber pressure the system is configured to provide a flowrate through the irrigation tube that is greater than the flowrate through the aspiration tube.
It has been found that the aspiration tube may become occluded during a procedure. The occlusion will increase the vacuum pressure within the aspiration line. When the occlusion is cleared the anterior chamber may be instantaneous exposed to a high vacuum pressure. The vacuum pressure may cause the cornea to collapse. It would be desirable to provide an aspiration system that minimizes the effects of a cleared occlusion within an aspiration tube of the system.
One embodiment of the present invention is an aspiration tube that has at least one pre-formed coil.